The efficient use of energy is nowadays a major concern. In the field of cargo transportation two particular economies can be identified; in the maximization of the use of space, and in the case of refrigerated or otherwise conditioned atmospheres in the vehicle the application of conditioning only to the minimum necessary volume.
Permanent partitions sub-dividing the interior are not effective if the size of loads or their make-up is not constant, and they will make loading and unloading more difficult.